Limnetica 40

The occurrence of Sigara (Subsigara) distincta (Fieber, 1848) in Spain is reported for the first time based on specimens collected in the Pyrenean municipality of Vielha e Mijaran (Central Pyrenees). Multiple captures between 2014-2018 indicate that S. distincta successfully established itself in Lake Vilac (1640 m a.s.l.), a small mesotrophic water body under Atlantic climate. High-throughput sequencing (HTS) technologies are valuable tools for freshwater bioassessment and detection of rare taxa. A DNA metabarcoding study carried out on macroinvertebrate samples supported the presence of S. distincta in the lake, thus corroborating morphological identification of imagines and greatly facilitating the identification of immature stages, which otherwise would be a difficult if not impossible task. By means of DNA barcode sequencing of individuals from Lake Vilac, we detected a rare haplotype of S. distincta previously recorded in Northern Germany. Our sequences showed to be clearly segregated from other publicly available S. distincta sequences, according to phylogenetic analysis. The results support the hypotheses of the existence of two highly divergent S. distincta lineages across Europe. A major taxonomic revision of Subsigara Stichel, 1935 species, combining both molecular and morphological approaches will be needed to shed light on the causes of high genetic intraspecific variation in S. distincta and related species.